The present invention relates to devices for connecting cables and electrical tubing to electrical panels or junction boxes and specifically to a device that is easier to use in a more universal manner than current connectors that are commonly used in the trade.
It is common in the electrical industry to connect cable and electrical tubing to electrical junction boxes by means of a variety of standard threaded connectors. The exterior threaded portion of the connectors are pushed into a standard access hole in a junction box or electrical panel and held in the hole by a standard lock nut. This standard lock nut has an interior-thread, which is screwed onto the exterior-threaded electrical connector that extends into the junction box. The lock nut typically has one or more individual threads on its interior circumference to create a locking grip against the wall of the junction box. Sometimes the access hole has internal threads into which the connector is threaded. In that case, no lock nut is needed. Lock nuts used in the electrical trade are commonly formed of metal that is 0.130 inches or more in thickness.
Also, snap fitting connectors are becoming more popular in situations that do not require a threaded lock nut.
While snap fitting connectors have become important, they are still limited to those installations where a locking nut is not desired or a threaded receiver access hole are not present.
Therefore, an acceptable and versatile snap fitting connector or snap ring that can also be removed for use with threaded lock nuts or threaded receptacles is very much needed. Efforts have been made in the past to achieve these goals, but the prior efforts are not believed to have been successful.
This invention provides a snap ring and threaded electrical connector that is much easier to use in a universal and versatile manner than the current connectors used in the trade. The snap ring is stamped from a single thin piece of spring steel or its equivalent. In the stamping procedure, locking tabs are formed to define portions that are bent inward to form locks for mating with apertures located in the leading end of a special connector and portions that form snap locking tangs. The stamped piece of spring steel is formed into a circular or annular shape thereby creating a ring shaped snap ring with snap locking tangs slanted to the rear and outward to snap in an access hole in an electrical junction box to prevent pull out. The snap ring also has inward and forward slanting locking tabs around its outer periphery to lock the locking tabs to an aperture in the forward portion of the electrical fitting. The locking tabs within the snap ring are sized, positioned and shaped to fit into the mating aperture in a manner it cannot be pulled forward or rotated relative to the connector. As used herein, the aperture is defined to include an opening or a locking recess as the aperture can be either open at the bottom or have a thin bottom wall. The thickness of the snap ring and its shape is critical as it must fit into the space between the outside diameter of the threaded portion of the connector with standard threads and the inside diameter of the standard access holes in the electrical junction box or panel. Grounding tangs are also lanced rearwardly and outwardly to provide a grounding contact.
To apply the snap ring with the threaded connector, the snap ring is placed over the threaded leading end with the locking tabs located in the locking apertures. The assembled connector and snap ring is then ready for use. When used, the installer simply has to insert the assembled connector into the access hole in the junction box until the flange prevents further insertion. During insertion, the snap locking tangs are forced inwardly by the sidewalls of the junction box hole until the tangs are completely through the hole at which time they snap back and prevent withdrawal. This is a single hand job and makes installation efficient and easy, even in difficult positions. The invention permits the use of the special connector of the invention with standard cable and electrical tubing with standard electrical junction boxes having standard holes.
In the event, it is desired to remove the snap ring, such can readily be done by a screwdriver or other tool or manually to unlock and remove the ring from the remainder of the fitting. This exposes the screw thread for use with a standard lock nut either when there is no thread opening in an electrical box or permits the connector to be threaded into a threaded receptacle.
Other advantages of the present invention will be better understood from the following description when read in conjunction with the appropriate drawings.